High-frequency module

ABSTRACT

In a high-frequency module, a first individual terminal in a switch IC is connected to a first filter and a third filter whose pass bands are far from each other. A low-pass-filter phase circuit including an inductor and a capacitor is connected between the first individual terminal and the first filter. A second individual terminal is connected to a second filter and a fourth filter whose pass bands are far from each other. A low-pass-filter phase circuit is connected between the second individual terminal and the second filter.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a high-frequency module that transmitsand receives multiple communication signals via a common antenna.

2. Description of the Related Art

Various high-frequency modules that transmit and receive multiplecommunication signals using different frequency bands with commonantennas have been proposed. For example, a high-frequency moduledisclosed in Japanese Unexamined Patent Application Publication No.2005-64778 includes a switch integrated circuit (IC) and multipleduplexers. An antenna is connected to a common terminal in the switch ICand the respective duplexers are connected to individual terminals inthe switch IC.

The high-frequency module disclosed in Japanese Unexamined PatentApplication Publication No. 2005-64778 has, for example, a circuitconfiguration shown in FIG. 1. FIG. 1 is a diagram showing the circuitconfiguration of a high-frequency module 10P. Only a reception systemcircuit will be simply described here. Referring to FIG. 1, a switch IC11 includes a common terminal PIC0 and individual terminals PIC11 toPIC16.

In reception of a Global System for Mobile Communication 850 (GSM850)communication signal and a GSM900 communication signal, the switch IC 11connects the common terminal PIC0 to the individual terminal PIC13. Inthis case, the GSM850 communication signal and the GSM900 communicationsignal received via an antenna ANT are transmitted to the individualterminal PIC13.

A surface acoustic wave (SAW) duplexer SDP12 including SAW filters SAW1and SAW2 is connected to the individual terminal PIC13. A phase circuitincluding a serially connected inductor L11 and a capacitor C11grounding one end of the inductor L11 is connected between theindividual terminal PIC13 and the SAW filter SAW1. A phase circuitincluding a serially connected capacitor C21 and an inductor L21grounding one end of the capacitor C21 is connected between theindividual terminal PIC13 and the SAW filter SAW2. In these phasecircuits, the element values are determined so that the SAW filter SAW2side is open (the reflection coefficient is maximized) for the GSM850communication signal and the SAW filter SAW1 side is open (thereflection coefficient is maximized) for the GSM900 communicationsignal. The element values are determined in the above manner to ensurea certain level or higher of isolation between the SAW filters SAW1 andSAW2.

Similarly, when receiving a GSM1800 communication signal and a GSM1900communication signal, the switch IC 11 connects the common terminal PIC0to the individual terminal PIC14. In this case, the GSM1800communication signal and the GSM1900 communication signal received viathe antenna ANT are transmitted to the individual terminal PIC14.

A SAW duplexer SDP34 including SAW filters SAW3 and SAW4 is connected tothe individual terminal PIC14. A phase circuit including a seriallyconnected inductor L31 and a capacitor C31 grounding one end of theinductor L31 is connected between the individual terminal PIC14 and theSAW filter SAW3. A phase circuit including a serially connectedcapacitor C41 and an inductor L41 grounding one end of the capacitor C41is connected between the individual terminal PIC14 and the SAW filterSAW4. In these phase circuits, the element values are determined so thatthe SAW filter SAW4 side is open (the reflection coefficient ismaximized) for the GSM1800 communication signal and the SAW filter SAW3side is open (the reflection coefficient is maximized) for the GSM1900communication signal. The element values are determined in the abovemanner to ensure a certain level or higher of isolation between the SAWfilters SAW3 and SAW4.

However, in the high-frequency module 10P described above, the passbands of the SAW filters composing the SAW duplexer connected to oneindividual terminal in the switch IC 11 are close to each other. Inother words, the frequency bands of the communication signals passingthrough the respective SAW filters are close to each other.

Accordingly, there are cases where it is not possible to set thefrequency bands so as to achieve transmission characteristics havingsufficiently low loss for the frequency band of one communicationsignal, among the two communication signals output from each individualterminal, and reflection characteristics sufficient for the frequencyband of the remaining communication signal.

SUMMARY OF THE INVENTION

Accordingly, preferred embodiments of the present invention provide ahigh-frequency module that has a configuration in which multiplecommunication signals are switched and received via a common antenna andthat is capable of transmitting two communication signals, among themultiple communication signals, to different ports with low loss even ifthe frequencies of the two communication signals are close to eachother.

According to a preferred embodiment of the present invention, ahigh-frequency module includes a switch IC including a common terminaland a plurality of individual terminals; and a plurality of filtersconnected to the individual terminals in the switch IC, for which a passband is set for each communication signal. The plurality of filters atleast include a first filter having a frequency of a first communicationsignal as the pass band, a second filter having a frequency of a secondcommunication signal as the pass band, the frequency band of the firstcommunication signal being close to the frequency band of the secondcommunication signal, and a third filter having a frequency of a thirdcommunication signal as the pass band, the frequency of the thirdcommunication signal being far from the frequencies of the firstcommunication signal and the second communication signal. The firstfilter and the third filter are connected to a first individual terminalin the switch IC. The second filter is connected to a second individualterminal in the switch IC.

With the above configuration, the first communication signal and thesecond communication signal whose frequencies are close to each otherare transmitted through different individual terminals in the switch IC.The first communication signal and the third communication signal whosefrequencies are far from each other are transmitted through the sameindividual terminal in the switch IC. Accordingly, since the frequenciesof the two communication signals transmitted through the same individualterminal are far from each other and the communication signals whosefrequencies are close to each other are transmitted through differentindividual terminals even in the configuration in which multiplecommunication signals are transmitted through one individual terminal,it is possible to easily realize the configuration capable of ensuringhigh isolation. In addition, the high-frequency module can be reduced insize, compared with the configuration in which different individualterminals are provided for different communication signals.

In the high-frequency module, when a plurality of communication signalscorresponding to the third communication signal exist, a communicationsignal whose phase variation within the frequency band is small andwhich has larger reflection strength for the first filter is preferablyset to the third communication signal.

The above configuration indicates a criterion for setting the thirdcommunication signal when multiple communication signals whosefrequencies are far from the frequencies of the first communicationsignal and the second communication signal exist. The thirdcommunication signal can be set in the above manner to reliably andeasily ensure high isolation between the transmission path of the firstcommunication signal including the first filter and the transmissionpath of the third communication signal including the third filter.

In the high-frequency module, the frequency of the first communicationsignal is preferably lower than the frequency of the third communicationsignal. A low-pass-filter phase circuit is preferably provided at leastone of between the first filter and the first individual terminal andbetween the second filter and the second individual terminal.

With the above configuration, the low-pass-filter phase circuit isprovided on the path through which the communication signal having arelatively low frequency is transmitted to improve the isolation.

The high-frequency module may further include a fourth filter having afrequency of a fourth communication signal whose frequency is close tothe frequency of the third communication signal as the pass band. Thefourth filter is preferably connected to a third individual terminal inthe switch IC.

In the high-frequency module having the above configuration, the fourthcommunication signal different from the first communication signal, thesecond communication signal, and the third communication signal is alsotransmitted and received. The fourth communication signal is, forexample, a communication signal that is not selected as the thirdcommunication signal when multiple candidates for the thirdcommunication signal exist. Since the fourth communication signal istransmitted through the individual terminal different from theindividual terminal through which the third communication signal istransmitted, it is possible to ensure high isolation between the firstcommunication signal, the second communication signal, the thirdcommunication signal, and the fourth communication signal.

The high-frequency module may further include a fourth filter having afrequency of a fourth communication signal whose frequency is close tothe frequency of the third communication signal as the pass band. Thefourth filter is preferably connected to the second individual terminalin the switch IC.

Also in the high-frequency module having the above configuration, thefourth communication signal different from the first communicationsignal, the second communication signal, and the third communicationsignal is transmitted and received. Since the fourth communicationsignal is transmitted through the individual terminal different from theindividual terminal through which the third communication signal istransmitted, it is possible to ensure high isolation between the firstcommunication signal, the second communication signal, the thirdcommunication signal, and the fourth communication signal. In addition,since the second communication signal and the fourth communicationsignal are transmitted through the same individual terminal, the numberof the individual terminals can be decreased to realize a more compacthigh-frequency module.

In the high-frequency module, the frequencies of the first communicationsignal and the second communication signal are preferably lower than thefrequency of the fourth communication signal. A high-pass-filter phasecircuit is preferably provided at least one of between the third filterand the first individual terminal and between the fourth filter and theindividual terminal connected to the fourth filter.

With the above configuration, since the high-pass-filter phase circuitis provided on the path on which the communication signal having arelatively high frequency is transmitted, it is possible to furtherimprove the isolation.

In the high-frequency module, the first filter, the second filter, thethird filter, and the fourth filter are preferably mounted filtersmounted in a multilayer body including dielectric layers. The firstfilter, the second filter, the third filter, and the fourth filter arepreferably mounted in any of the following mounting modes: (A) the firstfilter is mounted so as to be close to the third filter, (B) the secondfilter is mounted so as to be close to the fourth filter, or (C) thefirst filter is mounted so as to be close to the third filter and thesecond filter is mounted so as to be close to the fourth filter.

The above configurations indicate the specific mounting modes of thefilters. The filters whose pass bands are far from each other can bemounted so as to be close to each other to ensure isolation even in thecompact high-frequency module.

In the high-frequency module, a package duplexer is preferably includingthe first filter, the second filter, the third filter, and the fourthfilter in any of the following modes: (A) the first filter and the thirdfilter define a package duplexer, (B) the second filter and the fourthfilter define a package duplexer, or (C) the first filter and the thirdfilter define a package duplexer and the second filter and the fourthfilter define a package duplexer.

The above configurations indicate the specific configuration modes ofthe duplexer resulting from combinations of the filters. The duplexercan include the filters whose pass bands are far from each other torealize the compact high-frequency module with high isolation ensured.

According to various preferred embodiments of the present invention, itis possible to transmit two communication signals whose frequencies areclose to each other to different ports with low loss even in theconfiguration in which multiple communication signals including the twocommunication signals whose frequencies are close to each other areswitched via the common antenna to transmit and receive thecommunication signal after the switching.

The above and other elements, features, steps, characteristics andadvantages of the present invention will become more apparent from thefollowing detailed description of the preferred embodiments withreference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing the circuit configuration of ahigh-frequency module in the related art.

FIG. 2 is a diagram showing an example of the circuit configuration of ahigh-frequency module of a first preferred embodiment of the presentinvention.

FIGS. 3A to 3D are Smith charts for describing a concept that determinescombinations of communication signals in the first preferred embodimentof the present invention.

FIG. 4A shows a transmission characteristic of a GSM900 communicationsignal in the high-frequency module of the first preferred embodiment ofthe present invention and FIG. 4B shows a transmission characteristic ofthe GSM900 communication signal in the high-frequency module in therelated art.

FIG. 5 is a layer diagram of the high-frequency module of the firstpreferred embodiment of the present invention.

FIG. 6 is a diagram showing an example of the circuit configuration of ahigh-frequency module of a second preferred embodiment of the presentinvention.

FIG. 7 is a diagram showing an example of the circuit configuration of ahigh-frequency module of a third preferred embodiment of the presentinvention.

FIG. 8 is a diagram showing an example of the circuit configuration of ahigh-frequency module of a fourth preferred embodiment of the presentinvention.

FIG. 9 is a diagram showing an example of the circuit configuration of ahigh-frequency module of a fifth preferred embodiment of the presentinvention.

FIG. 10 is a diagram showing an example of the circuit configuration ofa high-frequency module of a sixth preferred embodiment of the presentinvention.

FIG. 11 is a layer diagram of the high-frequency module of the sixthpreferred embodiment of the present invention.

FIG. 12 is a diagram showing an example of the circuit configuration ofa high-frequency module of a seventh preferred embodiment of the presentinvention.

FIG. 13 is a diagram showing an example of the circuit configuration ofa high-frequency module of an eighth preferred embodiment of the presentinvention.

FIG. 14 is a diagram showing an example of the circuit configuration ofa high-frequency module of a ninth preferred embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A high-frequency module according to a first preferred embodiment of thepresent invention will now be described with reference to the drawings.The high-frequency module is exemplified by a high-frequency switchmodule that transmits and receives a GSM850 communication signal (havinga frequency within an about 850-MHz band), a GSM900 communication signal(having a frequency within a 900-MHz band), a GSM1800 communicationsignal (having a frequency within a 1800-MHz band), and a GSM1900communication signal (having a frequency within a 1900-MHz band) in thepresent preferred embodiment. FIG. 2 is a diagram showing an example ofthe circuit configuration of a high-frequency module 10A of the firstpreferred embodiment.

The high-frequency module 10A includes a switch IC 11, an antenna-sidematching circuit 12, a first transmission-side filter 13A, a secondtransmission-side filter 13B, and SAW duplexers SDP12 and SDP34. The SAWduplexer SDP12 includes a SAW filter SAW1 and a SAW filter SAW2. The SAWduplexer SDP34 includes a SAW filter SAW3 and a SAW filter SAW4.

The high-frequency module 10A includes a multilayer body in which acertain number of dielectric layers are laminated, circuit elements inthe multilayer body, and circuit elements mounted on the top surface ofthe multilayer body.

The switch IC 11 and the SAW duplexers SDP12 and SDP34 are mountedcircuit elements and are mounted on the top surface of the multilayerbody.

The antenna-side matching circuit 12 and the first and secondtransmission-side filters 13A and 13B schematically include inductorsand capacitors. The inductors and the capacitors of the antenna-sidematching circuit 12 and the first and second transmission-side filters13A and 13B are appropriately defined by either of inner-layer electrodepatterns in the multilayer body and mounted circuit elements.

The switch IC 11 includes a common terminal PIC0 and multiple (forexample, preferably six in the present preferred embodiment) individualterminals PIC11 to PIC16. A drive voltage Vdd and control voltages Vc1,Vc2, and Vc3 are applied to the switch IC 11. The switch IC 11 is drivenin response to the drive voltage Vdd that is applied. In the switch IC11, the common terminal PIC0 is connected to any of the individualterminals PIC11 to PIC16 in accordance with a combination of High andLow of the control voltages Vc1, Vc2, and Vc3.

The common terminal PIC0 in the switch IC 11 is connected to an antennaport Pan of the high-frequency module 10A via the antenna-side matchingcircuit 12. The antenna-side matching circuit 12 functions as a phasematching circuit and an electrostatic discharge (ESD) protection circuitin accordance with the connection configuration of the inductors and thecapacitors, which is appropriately set.

The individual terminal PIC11 in the switch IC 11 is connected to afirst transmission signal input port PtL of the high-frequency module10A via the first transmission-side filter 13A. A GSM850 transmissionsignal or a GSM900 transmission signal is input through the firsttransmission signal input port PtL. The first transmission-side filter13A has characteristics in that the transmission frequency bands of theGSM850 communication signal and the GSM900 communication signal areincluded in the pass band thereof and high-level harmonics includingsecond harmonics and third harmonics of the GSM850 communication signaland the GSM900 communication signal are included in the attenuation bandthereof.

The individual terminal PIC12 in the switch IC 11 is connected to asecond transmission signal input port PtH of the high-frequency module10A via the second transmission-side filter 13B. A GSM1800 transmissionsignal or a GSM1900 transmission signal is input through the secondtransmission signal input port PtH. The second transmission-side filter13B has characteristics in that the transmission frequency bands of theGSM1800 communication signal and the GSM1900 communication signal areincluded in the pass band thereof and high-level harmonics includingsecond harmonics and third harmonics of the GSM1800 communication signaland the GSM1900 communication signal are included in the attenuationband thereof.

The individual terminal PIC13 in the switch IC 11 is connected to theSAW filter SAW1 in the SAW duplexer SDP12 and the SAW filter SAW3 in theSAW duplexer SDP34.

The SAW filter SAW1 preferably is a SAW filter having abalanced-unbalanced transforming function and preferably is a filterusing the reception frequency band of the GSM850 communication signal asthe pass band. The unbalanced terminal of the SAW filter SAW1 isconnected to the individual terminal PIC13 and the balanced terminal ofthe SAW filter SAW1 is connected to a first reception signal output portPrL1 of the high-frequency module 10A.

The SAW filter SAW3 preferably is a SAW filter having thebalanced-unbalanced transforming function and preferably is a filterusing the reception frequency band of the GSM1800 communication signalas the pass band. The unbalanced terminal of the SAW filter SAW3 isconnected to the individual terminal PIC13 and the balanced terminal ofthe SAW filter SAW3 is connected to a third reception signal output portPrH1 of the high-frequency module 10A.

An inductor LA is connected between the individual terminal PIC13 andthe SAW filter SAW1 and the SAW filter SAW1 side of the inductor LA isgrounded via a capacitor CA, defining an L-type low pass filter circuitincluding the inductor LA and the capacitor CA. Providing a phasecircuit including the low pass filter circuit and appropriately settingthe element values of the inductor LA and the capacitor CA allows highisolation to be ensured between the transmission path at the SAW filterSAW1 side through which the GSM850 communication signal is transmittedand the transmission path at the SAW filter SAW3 side through which theGSM1800 communication signal is transmitted. In other words, it ispossible to ensure high isolation between the transmission path at theSAW filter SAW1 side connected to the individual terminal PIC13, whichis relatively at a lower frequency side, and the transmission path atthe SAW filter SAW3 side connected to the individual terminal PIC13,which is far from the pass band of the SAW filter SAW1 by a certainfrequency or more and which is relatively at a higher frequency side.

The individual terminal PIC14 in the switch IC 11 is connected to theSAW filter SAW2 in the SAW duplexer SDP12 and the SAW filter SAW4 in theSAW duplexer SDP34.

The SAW filter SAW2 preferably is a SAW filter having thebalanced-unbalanced transforming function and preferably is a filterusing the reception frequency band of the GSM900 communication signal asthe pass band. The unbalanced terminal of the SAW filter SAW2 isconnected to the individual terminal PIC14 and the balanced terminal ofthe SAW filter SAW2 is connected to a second reception signal outputport PrL2 of the high-frequency module 10A.

The SAW filter SAW4 preferably is a SAW filter having thebalanced-unbalanced transforming function and preferably is a filterusing the reception frequency band of the GSM1900 communication signalas the pass band. The unbalanced terminal of the SAW filter SAW4 isconnected to the individual terminal PIC14 and the balanced terminal ofthe SAW filter SAW4 is connected to a fourth reception signal outputport PrH2 of the high-frequency module 10A.

An inductor LB is connected between the individual terminal PIC14 andthe SAW filter SAW2 and the SAW filter SAW2 side of the inductor LB isgrounded via a capacitor CB, defining an L-type low pass filter circuitincluding the inductor LB and the capacitor CB. Providing a phasecircuit including the low pass filter circuit and appropriately settingthe element values of the inductor LB and the capacitor CB allows highisolation to be ensured between the transmission path at the SAW filterSAW2 side through which the GSM900 communication signal is transmittedand the transmission path at the SAW filter SAW4 side through which theGSM1900 communication signal is transmitted. In other words, it ispossible to ensure high isolation between the transmission path at theSAW filter SAW2 side connected to the individual terminal PIC14, whichis relatively at a lower frequency side, and the transmission path atthe SAW filter SAW4 side connected to the individual terminal PIC14,which is far from the pass band of the SAW filter SAW2 by a certainfrequency or more and which is relatively at a higher frequency side.

Combinations of the communication signals connected to one individualterminal are based on the following concept. FIGS. 3A to 3D are Smithcharts for describing the concept that determines the combinations ofthe communication signals. FIG. 3A shows input impedance characteristicsof the SAW filter SAW1 for the GSM850 communication signal, FIG. 3Bshows input impedance characteristics of the SAW filter SAW2 for theGSM900 communication signal, FIG. 3C shows input impedancecharacteristics of the SAW filter SAW3 for the GSM1800 communicationsignal, and FIG. 3D shows input impedance characteristics of the SAWfilter SAW4 for the GSM1900 communication signal.

As shown in FIG. 3A, in the SAW filter SAW1 for the GSM850 communicationsignal, the input impedance of the frequency band of the GSM1800communication signal is higher than that of the frequency band of theGSM900 communication signal (toward the periphery of the Smith chart).

Similarly, as shown in FIG. 3C, in the SAW filter SAW3 for the GSM1800communication signal, the input impedance of the frequency band of theGSM850 communication signal is higher than that of the frequency band ofthe GSM1900 communication signal.

Accordingly, it is possible to achieve higher isolation in theconfiguration (the configuration in the present preferred embodiment) inwhich the transmission path for the GSM850 communication signalincluding the SAW filter SAW1 and the transmission path for the GSM1800communication signal including the SAW filter SAW3 are connected to theindividual terminal PIC13, compared with the configuration (theconfiguration in the related art) in which the transmission path for theGSM850 communication signal including the SAW filter SAW1 and thetransmission path for the GSM900 communication signal including the SAWfilter SAW2 are connected to the individual terminal PIC13.

Furthermore, as shown in FIG. 3C, the amount of variation (a portionsurrounded by a solid line) in the input impedance within the frequencyband of the GSM850 communication signal is smaller than the amount ofvariation (a portion surrounded by a broken line) in the input impedancewithin the frequency band of the GSM1900 communication signal in the SAWfilter SAW3. Accordingly, the phase can be shifted toward the open side(toward the right side of the Smith chart) with the above phase circuitincluding the inductor and the capacitor to arrange the substantiallyentire area of the frequency band of the GSM850 communication signal atthe substantially open position. As a result, it is possible to furtherimprove the isolation.

As shown in FIG. 3B, in the SAW filter SAW2 for the GSM900 communicationsignal, the input impedance of the frequency band of the GSM1900communication signal is higher than that of the frequency band of theGSM850 communication signal (toward the periphery of the Smith chart).

Similarly, as shown in FIG. 3D, in the SAW filter SAW4 for the GSM1900communication signal, the input impedance of the frequency band of theGSM900 communication signal is higher than that of the frequency band ofthe GSM1800 communication signal.

Accordingly, it is possible to achieve higher isolation in theconfiguration (the configuration in the present preferred embodiment) inwhich the transmission path for the GSM900 communication signalincluding the SAW filter SAW2 and the transmission path for the GSM1900communication signal including the SAW filter SAW4 are connected to theindividual terminal PIC14, compared with the configuration (theconfiguration in the related art) in which the transmission path for theGSM1800 communication signal including the SAW filter SAW3 and thetransmission path for the GSM1900 communication signal including the SAWfilter SAW4 are connected to the individual terminal PIC14.

Furthermore, as shown in FIG. 3D, the amount of variation (a portionsurrounded by a solid line) in the input impedance within the frequencyband of the GSM900 communication signal is smaller than the amount ofvariation (a portion surrounded by a broken line) in the input impedancewithin the frequency band of the GSM1800 communication signal in the SAWfilter SAW4. Accordingly, the phase can be shifted toward the open side(toward the right side of the Smith chart) with the above phase circuitincluding the inductor and the capacitor to arrange the substantiallyentire area of the frequency band of the GSM900 communication signal atthe substantially open position. As a result, it is possible to furtherimprove the isolation.

FIGS. 4A and 4B show transmission characteristics of the GSM900reception signal in the high-frequency module 10A of the presentpreferred embodiment and the high-frequency module 10P in the relatedart. FIG. 4A shows the case in the high-frequency module 10A of thepresent preferred embodiment. FIG. 4B shows the case in thehigh-frequency module 10P in the related art.

As shown in FIGS. 4A and 4B, with the configuration of the presentpreferred embodiment, it is possible to reduce the loss to transmit theGSM900 reception signal with low loss. The configuration of the presentpreferred embodiment can be used to reduce the losses in the othercommunication signals, as apparent from the relationship shown in theSmith charts in FIGS. 3A to 3D, although not shown in FIGS. 4A and 4B.

As described above in the present preferred embodiment, twocommunication signals having frequency bands that are far from eachother can be allocated to one individual terminal to realize thehigh-frequency module with lower loss, compared with the configurationin the related art in which two communication signals having frequencybands that are close to each other are allocated to one individualterminal.

The high-frequency module 10A having the above circuit configuration hasthe following structure. Specifically, the high-frequency module 10Aincludes a multilayer body in which multiple dielectric layers PL1 toPL14 are laminated and various mounted circuit elements mounted on thetop surface of the multilayer body. FIG. 5 is a layer diagram of thehigh-frequency module 10A of the present preferred embodiment. In thelayer diagram in FIG. 5, the top layer at the top-surface side of themultilayer body corresponds to the first layer PL1 and the bottom layercorresponds to the fourteenth layer PL14. FIG. 5 is a plan view ofelectrode patterns from the bottom side. Circles indicated in therespective layers in FIG. 5 denote conductive via holes connecting thelayers.

Element mounted lands on which the mounted circuit elements includingthe switch IC 11, the SAW duplexers SDP12 and SDP34, the inductors LAand LB, and the capacitors CA and CB are mounted are arranged at thetop-surface side of the first layer PL1.

The SAW duplexer SDP12 is a mounted circuit element in which the SAWfilter SAW1 and the SAW filter SAW2 are incorporated in a single casing.The SAW duplexer SDP34 is a mounted circuit element in which the SAWfilter SAW3 and the SAW filter SAW4 are incorporated in a single casing.

Wiring pattern electrodes are arranged on the second layer PL2 and thethird layer PL3. The wiring pattern electrodes wire the respectiveelement mounted lands on the first layer PL1 into electrode portions onlower layers of the multilayer body.

An inner-layer ground electrode GND is arranged on the substantiallyentire area of the fourth layer PL4.

The circuit elements of the antenna-side matching circuit 12, the firsttransmission-side filter 13A, and the second transmission-side filter13B, excluding the circuit elements realized by the above mountedcircuit elements, are arranged on the fifth layer PL5 to the twelfthlayer PL12 as inner-layer electrode patterns.

An inner-layer ground electrode GND is arranged on the substantiallyentire area of the thirteenth layer PL13.

Various external connection lands are arranged on the bottom-surfaceside of the fourteenth layer PL14 of the bottom surface of themultilayer body. External connection ground electrodes GNDs are arrangedat the central portion in a plan view of the fourteenth layer PL14.

The external connection lands corresponding to the first receptionsignal output port PrL1, the second reception signal output port PrL2,the third reception signal output port PrH1, and the fourth receptionsignal output port PrH2 are aligned and arranged along the longitudinaldirection near one side surface along the longitudinal direction of thefourteenth layer PL14.

The external connection lands arranged to apply the drive voltage Vddand the control voltages Vc1 to Vc3 (corresponding to Vdd, Vc1, Vc2, andVc3 in FIG. 2) and the external connection land corresponding to theantenna port Pan are aligned and arranged along the longitudinaldirection near the other side surface along the longitudinal directionof the fourteenth layer PL14.

The external connection lands corresponding to the first transmissionsignal input port PtL and the second transmission signal input port PtHare arranged along the latitudinal direction near one side surface alongthe latitudinal direction of the fourteenth layer PL14.

The external connection lands corresponding to first and secondinput-output ports Pumt1 and Pumt2 are arranged along the latitudinaldirection near the other side surface along the latitudinal direction ofthe fourteenth layer PL14.

The high-frequency module 10A including the multilayer body and themounted circuit elements mounted on the multilayer body preferably hasthe above structure.

The use of the configuration described above in which multiple SAWfilters are connected to one individual terminal in the switch IC 11allows the multilayer body to be reduced in size, compared with theconfiguration in which one SAW filter is connected to each individualterminal.

The use of the configuration of the present preferred embodiment(devising the combinations of two SAW filters connected to eachindividual terminal), in addition to the configuration in which multipleSAW filters are connected to one individual terminal in the switch IC11, allows the compact high-frequency module capable of ensuring highisolation between the transmission paths of the communication signals tobe realized.

A high-frequency module according to a second preferred embodiment willnow be described with reference to FIG. 6. FIG. 6 is a diagram showingan example of the circuit configuration of a high-frequency module 10Bof the second preferred embodiment.

The high-frequency module 10B of the present preferred embodimentdiffers from the high-frequency module 10A of the first preferredembodiment in the circuit configuration connected to the individualterminals PIC13 and PIC14 in the switch IC 11, and the high-frequencymodule 10B of the present preferred embodiment is the same as thehigh-frequency module 10A of the first preferred embodiment in theremaining configuration. Only the difference from the high-frequencymodule 10A of the first preferred embodiment will be described here.

A capacitor CA2 is connected between the individual terminal PIC13 inthe switch IC 11 and the SAW filter SAW3 in the SAW duplexer SDP34 andthe SAW filter SAW3 side of the capacitor CA2 is grounded via aninductor LA2, defining an L-type high pass filter circuit including thecapacitor CA2 and the inductor LA2. Providing a phase circuit includingthe high pass filter circuit and appropriately setting the elementvalues of the capacitor CA2 and the inductor LA2 allows higher isolationto be ensured between the transmission path at the SAW filter SAW1 sidethrough which the GSM850 communication signal is transmitted and thetransmission path at the SAW filter SAW3 side through which the GSM1800communication signal is transmitted.

A capacitor CB2 is connected between the individual terminal PIC14 inthe switch IC 11 and the SAW filter SAW4 in the SAW duplexer SDP34 andthe SAW filter SAW4 side of the capacitor CB2 is grounded via aninductor LB2, defining an L-type high pass filter circuit including thecapacitor CB2 and the inductor LB2. Providing a phase circuit includingthe high pass filter circuit and appropriately setting the elementvalues of the capacitor CB2 and the inductor LB2 allows higher isolationto be ensured between the transmission path at the SAW filter SAW2 sidethrough which the GSM900 communication signal is transmitted and thetransmission path at the SAW filter SAW4 side through which the GSM1900communication signal is transmitted.

A high-frequency module according to a third preferred embodiment willnow be described with reference to FIG. 7. FIG. 7 is a diagram showingan example of the circuit configuration of a high-frequency module 10Cof the third preferred embodiment.

The high-frequency module 10C of the present preferred embodimentswitches between the GSM900 communication signal, the GSM1800communication signal, and the GSM1900 communication signal to transmitand receive the communication signal after the switching. Since thehigh-frequency module 10C basically differs from the high-frequencymodule 10A in the circuit configuration of the reception system of theswitch IC 11, only the circuit configuration of the reception systemwill be specifically described here.

The individual terminal PIC13 in the switch IC 11 is connected to thesingle SAW filter SAW2 and the SAW filter SAW3 in the SAW duplexerSDP34.

The unbalanced terminal of the SAW filter SAW2 is connected to theindividual terminal PIC13 and the balanced terminal of the SAW filterSAW2 is connected to the second reception signal output port PrL2 of thehigh-frequency module 10C. The unbalanced terminal of the SAW filterSAW3 is connected to the individual terminal PIC13 and the balancedterminal of the SAW filter SAW3 is connected to the third receptionsignal output port PrH1 of the high-frequency module 10C.

An inductor LA3 is connected between the individual terminal PIC13 andthe SAW filter SAW2 and the SAW filter SAW2 side of the inductor LA3 isgrounded via a capacitor CA3, defining an L-type low pass filter circuitincluding the inductor LA3 and the capacitor CA3.

A capacitor CA4 is connected between the individual terminal PIC13 andthe SAW filter SAW3 and the SAW filter SAW3 side of the capacitor CA4 isgrounded via an inductor LA4, defining an L-type high pass filtercircuit including the capacitor CA4 and the inductor LA4.

Providing phase circuits including the low pass filter circuit and thehigh pass filter circuit and appropriately setting the element values ofthe inductors LA3 and LA4 and the capacitors CA3 and CA4 allows highisolation to be ensured between the transmission path at the SAW filterSAW2 side through which the GSM900 communication signal is transmittedand the transmission path at the SAW filter SAW3 side through which theGSM1800 communication signal is transmitted.

The individual terminal PIC14 in the switch IC 11 is connected to theSAW filter SAW4 in the SAW duplexer SDP34. Although the SAW filter SAW4is integrated with the SAW filter SAW3 to define the SAW duplexer SDP34,the SAW filter SAW4 is connected to the individual terminal differentfrom the individual terminal to which the SAW filter SAW3 is connectedand, thus, high isolation can also be ensured between the transmissionpath for the GSM1900 communication signal and the transmission path foranother communication (for example, the GSM1800 communication signal).

A high-frequency module according to a fourth preferred embodiment willnow be described with reference to FIG. 8. FIG. 8 is a diagram showingan example of the circuit configuration of a high-frequency module 10Dof the fourth preferred embodiment. The high-frequency module 10D of thepresent preferred embodiment switches between the GSM900 communicationsignal, the GSM1800 communication signal, and the GSM1900 communicationsignal to transmit and receive the communication signal after theswitching, like the high-frequency module 10C of the third preferredembodiment. The high-frequency module 10D of the present preferredembodiment differs from the high-frequency module 10C of the thirdpreferred embodiment in that the SAW filter SAW4 is connected to theindividual terminal PIC13 and the SAW filter SAW3 is connected to theindividual terminal PIC14.

The individual terminal PIC13 in the switch IC 11 is connected to thesingle SAW filter SAW2 and the SAW filter SAW4 in the SAW duplexerSDP34.

The unbalanced terminal of the SAW filter SAW2 is connected to theindividual terminal PIC13 and the balanced terminal of the SAW filterSAW2 is connected to the second reception signal output port PrL2 of thehigh-frequency module 10D. The unbalanced terminal of the SAW filterSAW4 is connected to the individual terminal PIC13 and the balancedterminal of the SAW filter SAW4 is connected to the fourth receptionsignal output port PrH2 of the high-frequency module 10D.

An inductor LA5 is connected between the individual terminal PIC13 andthe SAW filter SAW2 and the SAW filter SAW2 side of the inductor LA5 isgrounded via a capacitor CA5, defining an L-type low pass filter circuitincluding the inductor LA5 and the capacitor CA5.

A capacitor CA6 is connected between the individual terminal PIC13 andthe SAW filter SAW4 and the SAW filter SAW4 side of the capacitor CA6 isgrounded via an inductor LA6, defining an L-type high pass filtercircuit including the capacitor CA6 and the inductor LA6.

Providing phase circuits including the low pass filter circuit and thehigh pass filter circuit and appropriately setting the element values ofthe inductors LA5 and LA6 and the capacitors CA5 and CA6 allows highisolation to be ensured between the transmission path at the SAW filterSAW2 side through which the GSM900 communication signal is transmittedand the transmission path at the SAW filter SAW4 side through which theGSM1900 communication signal is transmitted.

The individual terminal PIC14 in the switch IC 11 is connected to theSAW filter SAW3 in the SAW duplexer SDP34. Although the SAW filter SAW3is integrated with the SAW filter SAW4 to define the SAW duplexer SDP34,the SAW filter SAW3 is connected to the individual terminal differentfrom the individual terminal to which the SAW filter SAW4 is connectedand, thus, high isolation can also be ensured between the transmissionpath for the GSM1800 communication signal and the transmission path foranother communication (for example, the GSM1900 communication signal).

A high-frequency module according to a fifth preferred embodiment willnow be described with reference to FIG. 9. FIG. 9 is a diagram showingan example of the circuit configuration of a high-frequency module 10Eof the fifth preferred embodiment. Since the high-frequency module 10Eof the present preferred embodiment basically differs from thehigh-frequency module 10A in the circuit configuration of the receptionsystem of the switch IC 11, only the circuit configuration of thereception system will be specifically described here.

The individual terminal PIC13 in the switch IC 11 is connected to theSAW filter SAW1 in the SAW duplexer SDP12. The unbalanced terminal ofthe SAW filter SAW1 is connected to the individual terminal PIC13 andthe balanced terminal of the SAW filter SAW1 is connected to the firstreception signal output port PrL1 of the high-frequency module 10E.

The individual terminal PIC14 in the switch IC 11 is connected to theSAW filter SAW2 in the SAW duplexer SDP12 and the SAW filter SAW3 in theSAW duplexer SDP34. The unbalanced terminal of the SAW filter SAW2 isconnected to the individual terminal PIC14 and the balanced terminal ofthe SAW filter SAW2 is connected to the second reception signal outputport PrL2 of the high-frequency module 10E.

The unbalanced terminal of the SAW filter SAW3 is connected to theindividual terminal PIC14 and the balanced terminal of the SAW filterSAW3 is connected to the third reception signal output port PrH1 of thehigh-frequency module 10E.

An individual terminal PIC17 in the switch IC 11 is connected to the SAWfilter SAW4 in the SAW duplexer SDP34. The unbalanced terminal of theSAW filter SAW4 is connected to the individual terminal PIC17 and thebalanced terminal of the SAW filter SAW4 is connected to the fourthreception signal output port PrH2 of the high-frequency module 10E. Inother words, the unbalanced terminal of the SAW filter SAW2 in the SAWduplexer SDP12 and the unbalanced terminal of the SAW filter SAW3 in theSAW duplexer SDP34 are commonly used. Commonly using the unbalancedterminals of the SAW duplexers SDP12 and SDP34 in the above mannerallows the high-frequency module 10E to be further reduced in size. Inaddition, it is also possible to improve the degree of freedom in thedesign of the wiring patterns, etc. of the multilayer body.

An inductor LA7 is connected between the individual terminal PIC14 andthe SAW filter SAW2 and the SAW filter SAW2 side of the inductor LA7 isgrounded via a capacitor CA7, defining an L-type low pass filter circuitincluding the inductor LA7 and the capacitor CA7.

A capacitor CA8 is connected between the individual terminal PIC14 andthe SAW filter SAW3 and the SAW filter SAW3 side of the capacitor CA8 isgrounded via an inductor LA8, defining an L-type high pass filtercircuit including the capacitor CA8 and the inductor LA8.

Providing phase circuits including the low pass filter circuit and thehigh pass filter circuit and appropriately setting the element values ofthe inductors LA7 and LA8 and the capacitors CA7 and CA8 allows highisolation to be ensured between the transmission path at the SAW filterSAW2 side through which the GSM900 communication signal is transmittedand the transmission path at the SAW filter SAW3 side through which theGSM1800 communication signal is transmitted.

A high-frequency module according to a sixth preferred embodiment willnow be described with reference to FIGS. 10 and 11. FIG. 10 is a diagramshowing an example of the circuit configuration of a high-frequencymodule 10F of the sixth preferred embodiment. Since the high-frequencymodule 10F of the present preferred embodiment basically differs fromthe high-frequency module 10A in the circuit configuration of thereception system of the switch IC 11, only the circuit configuration ofthe reception system will be specifically described here.

The individual terminal PIC13 in the switch IC 11 is connected to theSAW filters SAW1 and SAW3 in a SAW duplexer SDP13. The SAW duplexerSDP13 is a circuit element in which the SAW filters SAW1 and SAW3 areincorporated in a single casing.

The unbalanced terminal of the SAW filter SAW1 is connected to theindividual terminal PIC13 and the balanced terminal of the SAW filterSAW1 is connected to the first reception signal output port PrL1 of thehigh-frequency module 10F. The unbalanced terminal of the SAW filterSAW3 is connected to the individual terminal PIC13 and the balancedterminal of the SAW filter SAW3 is connected to the third receptionsignal output port PrH1 of the high-frequency module 10F.

An inductor LA10 is connected between the individual terminal PIC13 andthe SAW filter SAW1 and the SAW filter SAW1 side of the inductor LA10 isgrounded via a capacitor CA10, defining an L-type low pass filtercircuit including the inductor LA10 and the capacitor CA10.

Providing a phase circuit including the low pass filter circuit andappropriately setting the element values of the inductor LA10 and thecapacitor CA10 allows high isolation to be ensured between thetransmission path at the SAW filter SAW1 side through which the GSM850communication signal is transmitted and the transmission path at the SAWfilter SAW3 side through which the GSM1800 communication signal istransmitted. In other words, operational effects similar to those in theabove preferred embodiments can be achieved even when the SAW filtersSAW1 and SAW3 connected to the individual terminal PIC13 define thesingle SAW duplexer SDP13.

The individual terminal PIC14 in the switch IC 11 is connected to theSAW filters SAW2 and SAW4 in a SAW duplexer SDP24. The SAW duplexerSDP24 is a circuit element in which the SAW filters SAW2 and SAW4 areincorporated in a single casing.

The unbalanced terminal of the SAW filter SAW2 is connected to theindividual terminal PIC14 and the balanced terminal of the SAW filterSAW2 is connected to the second reception signal output port PrL2 of thehigh-frequency module 10F. The unbalanced terminal of the SAW filterSAW4 is connected to the individual terminal PIC14 and the balancedterminal of the SAW filter SAW4 is connected to the fourth receptionsignal output port PrH2 of the high-frequency module 10F.

An inductor LB10 is connected between the individual terminal PIC14 andthe SAW filter SAW2 and the SAW filter SAW2 side of the inductor LB10 isgrounded via a capacitor CB10, defining an L-type low pass filtercircuit including the inductor LB10 and the capacitor CB10.

Providing a phase circuit including the low pass filter circuit andappropriately setting the element values of the inductor LB10 and thecapacitor CB10 allows high isolation to be ensured between thetransmission path at the SAW filter SAW2 side through which the GSM900communication signal is transmitted and the transmission path at the SAWfilter SAW4 side through which the GSM1900 communication signal istransmitted. In other words, operational effects similar to those in theabove preferred embodiments can be achieved even when the SAW filtersSAW2 and SAW4 connected to the individual terminal PIC14 define thesingle SAW duplexer SDP24.

The high-frequency module 10F of the present preferred embodiment doesnot have the configuration in which the SAW filters having frequencybands that are close to each other as the pass bands are incorporated ina single casing, such as the configuration of the high-frequency module10A of the first preferred embodiment described above, but has theconfiguration in which the SAW filters having frequency bands that arefar from each other as the pass bands are incorporated in a singlecasing.

Even with the above configuration, it is possible to realize thehigh-frequency module including the multilayer body, as in the firstpreferred embodiment and the like. FIG. 11 is a layer diagram of thehigh-frequency module 10F of the present preferred embodiment. Since thelayer structure of the high-frequency module 10F of the presentpreferred embodiment is substantially the same as the layer structure ofthe high-frequency module 10A of the first preferred embodiment, adetailed description of the layer structure of the high-frequency module10F is omitted herein.

In the layer structure of the present preferred embodiment, thecapacitor in the phase circuit provided between each individual terminaland the corresponding SAW duplexer is defined by an inner-layerelectrode pattern in the multilayer body. The capacitor may be providedin the multilayer body on the basis of desired characteristics in theabove manner. In this case, providing one opposing electrode on thelayer close to the inner-layer ground electrode and using theinner-layer ground electrode as the other opposing electrode allowsdesired isolation to be more accurately achieved.

A high-frequency module according to a seventh preferred embodiment willnow be described with reference to FIG. 12. FIG. 12 is a diagram showingan example of the circuit configuration of a high-frequency module 10Gof the seventh preferred embodiment. Since the high-frequency module 10Gof the present preferred embodiment basically differs from thehigh-frequency module 10A in the circuit configuration of the receptionsystem of the switch IC 11, as in the high-frequency module 10F, onlythe circuit configuration of the reception system will be specificallydescribed here.

The individual terminal PIC13 in the switch IC 11 is connected to theSAW filters SAW2 and SAW3 in a SAW duplexer SDP23. The SAW duplexerSDP23 is a circuit element in which the SAW filters SAW2 and SAW3 areincorporated in a single casing.

The unbalanced terminal of the SAW filter SAW2 is connected to theindividual terminal PIC13 and the balanced terminal of the SAW filterSAW2 is connected to the second reception signal output port PrL2 of thehigh-frequency module 10G. The unbalanced terminal of the SAW filterSAW3 is connected to the individual terminal PIC13 and the balancedterminal of the SAW filter SAW3 is connected to the third receptionsignal output port PrH1 of the high-frequency module 10G.

An inductor LA11 is connected between the individual terminal PIC13 andthe SAW filter SAW2 and the SAW filter SAW2 side of the inductor LA11 isgrounded via a capacitor CA11, defining an L-type low pass filtercircuit including the inductor LA11 and the capacitor CA11.

Providing a phase circuit including the low pass filter circuit andappropriately setting the element values of the inductor LA11 and thecapacitor CA11 allows high isolation to be ensured between thetransmission path at the SAW filter SAW2 side through which the GSM900communication signal is transmitted and the transmission path at the SAWfilter SAW3 side through which the GSM1800 communication signal istransmitted. In other words, operational effects similar to those in theabove preferred embodiments can be achieved even when the SAW filtersSAW2 and SAW3 connected to the individual terminal PIC13 define thesingle SAW duplexer SDP23.

The individual terminal PIC14 in the switch IC 11 is connected to theSAW filters SAW1 and SAW4 in a SAW duplexer SDP14. The SAW duplexerSDP14 is a circuit element in which the SAW filters SAW1 and SAW4 areincorporated in a single casing.

The unbalanced terminal of the SAW filter SAW1 is connected to theindividual terminal PIC14 and the balanced terminal of the SAW filterSAW1 is connected to the first reception signal output port PrL1 of thehigh-frequency module 10G. The unbalanced terminal of the SAW filterSAW4 is connected to the individual terminal PIC14 and the balancedterminal of the SAW filter SAW4 is connected to the fourth receptionsignal output port PrH2 of the high-frequency module 10G.

An inductor LB11 is connected between the individual terminal PIC14 andthe SAW filter SAW1 and the SAW filter SAW1 side of the inductor LB11 isgrounded via a capacitor CB11, defining an L-type low pass filtercircuit including the inductor LB11 and the capacitor CB11.

Providing a phase circuit including the low pass filter circuit andappropriately setting the element values of the inductor LB11 and thecapacitor CB11 allows high isolation to be ensured between thetransmission path at the SAW filter SAW1 side through which the GSM850communication signal is transmitted and the transmission path at the SAWfilter SAW4 side through which the GSM1900 communication signal istransmitted. In other words, operational effects similar to those in theabove preferred embodiments can be achieved even when the SAW filtersSAW1 and SAW4 connected to the individual terminal PIC14 define thesingle SAW duplexer SDP14.

A high-frequency module according to an eighth preferred embodiment willnow be described with reference to FIG. 13. FIG. 13 is a diagram showingan example of the circuit configuration of a high-frequency module 10Hof the eighth preferred embodiment. Since the high-frequency module 10Hof the present preferred embodiment basically differs from thehigh-frequency module 10A in the circuit configuration of the receptionsystem of the switch IC 11, only the circuit configuration of thereception system will be specifically described here.

An individual terminal PIC18 in the switch IC 11 is connected to SAWfilters SAW5 and SAW6 in a SAW duplexer SDP56. The SAW duplexer SDP56 isa circuit element in which the SAW filters SAW5 and SAW6 areincorporated in a single casing.

The SAW filter SAW5 preferably is a SAW filter having thebalanced-unbalanced transforming function and preferably is a filterusing the frequency band including both the reception frequency band ofthe GSM850 communication signal and the reception frequency band of theGSM900 communication signal as the pass band. The unbalanced terminal ofthe SAW filter SAW5 is connected to the individual terminal PIC18 andthe balanced terminal of the SAW filter SAW5 is connected to a fifthreception signal output port PrL12 of the high-frequency module 10H.

The SAW filter SAW6 preferably is a SAW filter having thebalanced-unbalanced transforming function and is a filter using thefrequency band including both the reception frequency band of theGSM1800 communication signal and the reception frequency band of theGSM1900 communication signal as the pass band. The unbalanced terminalof the SAW filter SAW6 is connected to the individual terminal PIC18 andthe balanced terminal of the SAW filter SAW6 is connected to a sixthreception signal output port PrH12 of the high-frequency module 10H.

An inductor LA20 is connected between the individual terminal PIC18 andthe SAW filter SAW5 and the SAW filter SAW5 side of the inductor LA20 isgrounded via a capacitor CA20, defining an L-type low pass filtercircuit including the inductor LA20 and the capacitor CA20.

A capacitor CB20 is connected between the individual terminal PIC18 andthe SAW filter SAW6 and the SAW filter SAW6 side of the capacitor CB20is grounded via an inductor LB20, defining an L-type high pass filtercircuit including the capacitor CB20 and the inductor LB20.

Providing phase circuits including the low pass filter circuit and thehigh pass filter circuit and appropriately setting the element values ofthe inductors LA20 and LB20 and the capacitors CA20 and CB20 allows highisolation to be ensured between the transmission path at the SAW filterSAW5 side through which the GSM850 communication signal and the GSM900communication signal are transmitted and the transmission path at theSAW filter SAW6 side through which the GSM1800 communication signal andthe GSM1900 communication signal are transmitted.

With the configuration of the present preferred embodiment, it ispossible to reduce the number of the individual terminals in the switchIC 11, the number of the SAW filters and the SAW duplexers, and thenumber of the external connection ports, thereby realizing the morecompact high-frequency module.

A high-frequency module according to a ninth preferred embodiment willnow be described with reference to FIG. 14. FIG. 14 is a diagram showingan example of the circuit configuration of a high-frequency module 10Jof the ninth preferred embodiment. The high-frequency module 10J of thepresent preferred embodiment switches between two Time DivisionSynchronous Code Division Multiple Access (TDSCDMA) communicationsignals: a TDSCDMA1.9 communication signal (having a frequency within a1.9-GHz band) and a TDSCDMA2.0 communication signal (having a frequencywithin a 2.0-GHz band), in addition to the GSM communication signalsdescribed in the above preferred embodiments, with the single antennaANT to transmit and receive the communication signal after theswitching. The high-frequency module 10J of the present preferredembodiment has the same basic configuration and concept as those of thehigh-frequency module 10A of the first preferred embodiment. Only pointsdifferent from the high-frequency module 10A of the first preferredembodiment will be specifically described here.

An individual terminal PIC21 in the switch IC 11 is connected to a thirdtransmission signal input port PtCD of the high-frequency module 10J viaa third transmission-side filter 13C. A TDSCDMA1.9 transmission signalor a TDSCDMA2.0 transmission signal is input through the thirdtransmission signal input port PtCD. The third transmission-side filter13C has characteristics in that the transmission frequency bands of theTDSCDMA1.9 communication signal and the TDSCDMA2.0 communication signalare included in the pass band thereof and high-level harmonics includingsecond harmonics and third harmonics of the TDSCDMA1.9 communicationsignal and the TDSCDMA2.0 communication signal are included in theattenuation band thereof.

The individual terminal PIC13 in the switch IC 11 is connected to theSAW filter SAW1 in the SAW duplexer SDP12 and a SAW filter SAW7 in a SAWduplexer SDP78.

The SAW filter SAW1 preferably is a SAW filter having thebalanced-unbalanced transforming function and is a filter using thereception frequency band of the GSM850 communication signal as the passband. The unbalanced terminal of the SAW filter SAW1 is connected to theindividual terminal PIC13 and the balanced terminal of the SAW filterSAW1 is connected to the first reception signal output port PrL1 of thehigh-frequency module 10J.

The SAW filter SAW7 preferably is a SAW filter having thebalanced-unbalanced transforming function and is a filter using thereception frequency band of the TDSCDMA1.9 communication signal as thepass band. The unbalanced terminal of the SAW filter SAW7 is connectedto the individual terminal PIC13 and the balanced terminal of the SAWfilter SAW7 is connected to a seventh reception signal output port PrCD1of the high-frequency module 10J.

An inductor LA30 is connected between the individual terminal PIC13 andthe SAW filter SAW1 and the SAW filter SAW1 side of the inductor LA30 isgrounded via a capacitor CA30, defining an L-type low pass filtercircuit including the inductor LA30 and the capacitor CA30. Providing aphase circuit including the low pass filter circuit and appropriatelysetting the element values of the inductor LA30 and the capacitor CA30allows high isolation to be ensured between the transmission path at theSAW filter SAW1 side through which the GSM850 communication signal istransmitted and the transmission path at the SAW filter SAW7 sidethrough which the TDSCDMA1.9 communication signal is transmitted.

An individual terminal PIC19 in the switch IC 11 is connected to the SAWfilter SAW2 in the SAW duplexer SDP12 and a SAW filter SAW8 in the SAWduplexer SDP78.

The SAW filter SAW2 preferably is a SAW filter having thebalanced-unbalanced transforming function and is a filter using thereception frequency band of the GSM900 communication signal as the passband. The unbalanced terminal of the SAW filter SAW2 is connected to theindividual terminal PIC19 and the balanced terminal of the SAW filterSAW2 is connected to the second reception signal output port PrL2 of thehigh-frequency module 10J.

The SAW filter SAW8 preferably is a SAW filter having thebalanced-unbalanced transforming function and preferably is a filterusing the reception frequency band of the TDSCDMA2.0 communicationsignal as the pass band. The unbalanced terminal of the SAW filter SAW8is connected to the individual terminal PIC19 and the balanced terminalof the SAW filter SAW8 is connected to an eighth reception signal outputport PrCD2 of the high-frequency module 10J.

An inductor LB30 is connected between the individual terminal PIC19 andthe SAW filter SAW2 and the SAW filter SAW2 side of the inductor LB30 isgrounded via a capacitor CB30, defining an L-type low pass filtercircuit including the inductor LB30 and the capacitor CB30. Providing aphase circuit including the low pass filter circuit and appropriatelysetting the element values of the inductor LB30 and the capacitor CB30allows high isolation to be ensured between the transmission path at theSAW filter SAW2 side through which the GSM900 communication signal istransmitted and the transmission path at the SAW filter SAW8 sidethrough which the TDSCDMA2.0 communication signal is transmitted.

The individual terminal PIC14 in the switch IC 11 is connected to theSAW filters SAW3 and SAW4 in the SAW duplexer SDP34. The SAW filter SAW3preferably is a SAW filter having the balanced-unbalanced transformingfunction and is a filter using the reception frequency band of theGSM1800 communication signal as the pass band. The unbalanced terminalof the SAW filter SAW3 is connected to the individual terminal PIC14 andthe balanced terminal of the SAW filter SAW3 is connected to the thirdreception signal output port PrH1 of the high-frequency module 10J. TheSAW filter SAW4 preferably is a SAW filter having thebalanced-unbalanced transforming function and preferably is a filterusing the reception frequency band of the GSM1900 communication signalas the pass band. The unbalanced terminal of the SAW filter SAW4 isconnected to the individual terminal PIC14 and the balanced terminal ofthe SAW filter SAW4 is connected to the fourth reception signal outputport PrH2 of the high-frequency module 10J.

A terminal common to the SAW filters SAW3 and SAW4 is provided at theunbalanced terminal side of the SAW duplexer SDP34. The transmissionpath between the common terminal of the SAW duplexer SDP34 and theindividual terminal PIC14 is grounded at a certain position with aninductor L22.

Also with the above configuration, it is possible to realize the compacthigh-frequency module with low loss.

The high-frequency modules described in the above preferred embodimentsindicate only examples embodying the features of the present invention.Any of the above configurations is applicable to a high-frequency modulethat transmits and receives three or more communication signals at leastincluding two communication signals whose frequencies are close to eachother and a communication signal having a frequency that is far from thefrequencies of the two communication signals by a certain frequency ormore with a common antenna by using a switch IC and filters. Althoughthe examples preferably using the SAW filters in the reception systemcircuit are described above, other filter circuits may be used.

Specific concepts of the communication signals whose frequencies areclose to each other and the communication signals whose frequencies arefar from each other are not accurately described in the abovedescription. For example, the communication signals whose frequenciesare close to each other may be communication signals whose frequencybands are partially overlapped in the transmission band and thereception band or communication signals whose frequency bands are in thesame order (for example, 100-MHz order). The communication signals whosefrequencies are far from each other may be communication signals whosefrequency bands are spaced apart from each other by a certain frequencyor more or communication signals whose frequency bands are in differentorders (for example, 100-MHz order and 1-GHz order). When threecommunication signals having different frequency bands exist, twocommunication signals having relatively close frequency bands may be setas the communication signals whose frequencies are close to each otherand the remaining communication signal whose frequency band isrelatively far from the frequency bands of the other two communicationsignals may be set as the communication signal whose frequency is farfrom those of the other communication signals.

While preferred embodiments of the present invention have been describedabove, it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the present invention. The scope of the present invention,therefore, is to be determined solely by the following claims.

1. A high-frequency module comprising: a switch IC including a commonterminal and a plurality of individual terminals; and a plurality offilters connected to the individual terminals in the switch IC, forwhich a pass band is set for each communication signal; wherein theplurality of filters at least include a first filter having a frequencyof a first communication signal as the pass band, a second filter havinga frequency of a second communication signal as the pass band, thefrequency band of the first communication signal being close to thefrequency band of the second communication signal, and a third filterhaving a frequency of a third communication signal as the pass band, thefrequency of the third communication signal being far from thefrequencies of the first communication signal and the secondcommunication signal; the first filter and the third filter areconnected to a first individual terminal in the switch IC; and thesecond filter is connected to a second individual terminal in the switchIC.
 2. The high-frequency module according to claim 1, wherein, when aplurality of communication signals corresponding to the thirdcommunication signal exist, a communication signal whose phase variationwithin the frequency band is small and which has larger reflectionstrength for the first filter is set to the third communication signal.3. The high-frequency module according to claim 1, wherein the frequencyof the first communication signal is lower than the frequency of thethird communication signal, and a low-pass-filter phase circuit isprovided at least one of between the first filter and the firstindividual terminal and between the second filter and the secondindividual terminal.
 4. The high-frequency module according to claim 1,further comprising a fourth filter having a frequency of a fourthcommunication signal whose frequency is close to the frequency of thethird communication signal as the pass band, wherein the fourth filteris connected to a third individual terminal in the switch IC.
 5. Thehigh-frequency module according to claim 1, further comprising a fourthfilter having a frequency of a fourth communication signal whosefrequency is close to the frequency of the third communication signal asthe pass band, wherein the fourth filter is connected to the secondindividual terminal in the switch IC.
 6. The high-frequency moduleaccording to claim 4, wherein the frequencies of the first communicationsignal and the second communication signal are lower than the frequencyof the fourth communication signal, and a high-pass-filter phase circuitis provided at least one of between the third filter and the firstindividual terminal and between the fourth filter and the individualterminal connected to the fourth filter.
 7. The high-frequency moduleaccording to claim 4, wherein the first filter, the second filter, thethird filter, and the fourth filter are mounted filters mounted in amultilayer body including dielectric layers, and the first filter ismounted so as to be close to the third filter, the second filter ismounted so as to be close to the fourth filter, or the first filter ismounted so as to be close to the third filter and the second filter ismounted so as to be close to the fourth filter.
 8. The high-frequencymodule according to claim 7, wherein the first filter and the thirdfilter define a package duplexer, the second filter and the fourthfilter define a package duplexer, or the first filter and the thirdfilter define a package duplexer and the second filter and the fourthfilter define a package duplexer.